How to open the default mail inbox from android code?

Solution 1:

If the goal is to open the default email app to view the inbox, then key is to add an intent category and use the ACTION_MAIN intent like so:

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_APP_EMAIL);
getActivity().startActivity(intent);

https://developer.android.com/reference/android/content/Intent.html#CATEGORY_APP_EMAIL

Solution 2:

This code worked for me. It opens a picker with all email apps registered to device and straight to Inbox:

Intent emailIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("mailto:"));
    PackageManager pm = getPackageManager();

    List<ResolveInfo> resInfo = pm.queryIntentActivities(emailIntent, 0);
    if (resInfo.size() > 0) {
        ResolveInfo ri = resInfo.get(0);
        // First create an intent with only the package name of the first registered email app
        // and build a picked based on it
        Intent intentChooser = pm.getLaunchIntentForPackage(ri.activityInfo.packageName);
        Intent openInChooser =
                Intent.createChooser(intentChooser,
                        getString(R.string.user_reg_email_client_chooser_title));

        // Then create a list of LabeledIntent for the rest of the registered email apps 
        List<LabeledIntent> intentList = new ArrayList<LabeledIntent>();
        for (int i = 1; i < resInfo.size(); i++) {
            // Extract the label and repackage it in a LabeledIntent
            ri = resInfo.get(i);
            String packageName = ri.activityInfo.packageName;
            Intent intent = pm.getLaunchIntentForPackage(packageName);
            intentList.add(new LabeledIntent(intent, packageName, ri.loadLabel(pm), ri.icon));
        }

        LabeledIntent[] extraIntents = intentList.toArray(new LabeledIntent[intentList.size()]);
        // Add the rest of the email apps to the picker selection
        openInChooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, extraIntents);
        startActivity(openInChooser);
    }

Solution 3:

Any suggestions to avoid the crash if the default mail in the device is not configured?

Yes, it's possible to open the Android default email inbox.
Use this code:

Intent intent = getPackageManager().getLaunchIntentForPackage("com.android.email");
startActivity(intent);

This code works, you have to configure your Android device default mail first. If you already configured your mail it works fine. Otherwise, it force closes with a NullPointerException.